Extension device



Jan. l2, 1932.

J. M. DALLAS EXTENSION DEVICE Filed May 4, 1929 2 Sheets-Sheet l Jan. 12, 1932. M, DALLAS 1 1,841,278

I EXTENSION DEVICE Filed May 4, 1929 2 Sheets-Sheet 2 Patented Jan. 12, i

UNITED JOHN m. DALLAS, or rrrrrenlighg am ness Application fiied ma' e, 1329 semi My invention relates to ,a new and useful improvement in extension devices and has for its ob ect to so construct such adevice as to provide for sustaining strains fromevery irection thereby producing a rigid structure at every point of extension.

A further object, of my invention is to provide for the nesting. of the-leversfcom v posing the device so that said device may 1 collapse within the space occupied by the outer lever. w With these and other' objects in view, this invention consists in the details of construction and combination of elementshere nafter set forth and then specifically designated by the claim. v V,

I In order that those skilled inwthefart-to which this invention appertains may understand how to make and use the same, I will describe its construction in detail, referring by numerals to the accompanying drawings forming a part of this application, in

which Fig. 1 is a side elevation of the device shown distended. r

*Fig. 2 is a plan view of Fig. 1. V

Fig. 3 is a-perspective of one of the female levers entering into the structure of the device. r

' Fig. 4: is a persp ctive ofoneofthe male levers. V 1 r Fig. 5' is a view similar .to-Fig. l looking from the opposite side. r

Fig. 6 is a section atthe line. ,6-.-6"of v Fig. 7 is a side elevation its collapsed position.

In carrying out myunventionfas herein embodied, 10 represents the female levers;

of the devicejin each of which is rectangular in form and"; comprising the outer sidebars lland the: inner side bars 12, so 7 as tov provide the spaces 13 into which the side bars "of the corresponding male lever". swing as hereinafter explained [The bars 11 terminate below the vertical center'of the female levers for the purpose hereinafter explained." g I In order that thesejfemale levers may be properly strengthened toresist strains from "bars l6;the latter connec ng "side b bars of the levers lfhwhile ftlm .lovvercrpssq'bars' of.;;the levers" 17 will pass= 26. While the inner portions of the inner male 3:

V which link is pivoted within said casing as s suchas to cause-the device in collapsing or in device is used; for, this purpose, one of'it's great. advantages is that it. may be collapsed strum'ent to be moved to a -considerable, dis-"j I I j itance fromjthe' casingf-26 and yetlprevent {3P 'undnejswinging or vibrationfof such instrug p g tfit which is of great advantage in this when distended.

tension device renders it especially adaptable at p sie e thirlse ifia the .snes s 3 e iithe w' tiso side inside ofith e -cross bars of these levers 10, 1

thus permitting all the levers to nest. f

assuming the positionshown in Fig. 7. I

When the device is to be used for holding a telephone instrument orthe. like, the lower 1 ends of one of the female levers are pivoted I as indicated at 25 within the box orcasing;

levers are. pivoted to .thelinks 2721s at 28,7

at 29 and'the distance of the pivotpoint 28 from the pivot point 29 relative to the length I of the link 27, and thepivot points 29 are being extended, to moveon parallel lines orremain nla horizontal position. W'hen'the intogajsmall space or within the casing and therefore suflicient levers maybe includedin p 7 its construction to" permit the telephone. ina 1 The inner ends of the inner-male levercar ries the studs '80 adapted to slide in the slots 31 which serve .to limit the extensionjof the device and also to add rigidity to the device The'rigid constructionofmy improved exused with great advantage in launching life device with special reference to its use for dredging booms and landing masts for diric gible flying machines, and it may also be saving boatsand rafts from ships at sea in d1stress, s1nce insuch cases, boatssuspended from the outer end of the device may be extended considerably beyond the hull of the vessel before being -1owefed,jand thus over come the serious disadvantage'attending such launchings, and therefore, of course I donot i wish to'be limited to the exact detailsofcon 7 struction as herein shown, as these'may be varied within the' limits of the {appended claims without my invention'k Having thus fully described my invention,p

whatl claim asnew and useful is I An extension device comprising a series of male and a series ofqfemale levers, each of rectangular form, each female member con-v sisting of two pairs of bars, so related as to form spaces, each male member consisting oftwo side bars, each of which bars is pivoted between a pair of bars of the female member to permit the nesting ofthe members whenthe device is collapsed.

In testimony whereof, I have hereunto afli'xed my signature. V 1

I j c. JOHN M. DALLAS.

departing from the spirit of; f 

